Re: Bug#563882: git-core FTBFS on ia64: t1001-read-tree-m-2way.sh test fails

[Jonathan Nieder <jrnieder@gmail.com>]

Bastian Blank wrote:

> On Tue, Jan 26, 2010 at 01:48:34PM -0600, Jonathan Nieder wrote:
> > severity 563882 critical
> 
> Please explain. git is neither unrelated to glibc nor does this cause
> serious data loss.

My mistake, sorry about that.

> The test program does not properly show what is going on.
> 
> The following program shows the cause:
> 
> | #include <sys/stat.h>
> | #include <sys/mman.h>
> | #include <fcntl.h>
> | 
> | int main(int argc, const char * const argv[])
> | { 
> |   struct stat st;
> |   lstat(argv[1], &st);
> | 
> |   int fd = open(argv[1], O_RDONLY);
> |   void *data = mmap(NULL, st.st_size, PROT_READ, MAP_PRIVATE, fd, 0);
> |   void *t = memchr(data, 0, st.st_size);
> |   printf("ptr: %p, ret: %p, len: 0x%zx\n", data, t, st.st_size);
> |   return 0;
> | }
> 
> Example output:
> | % ./test /etc/passwd
> | ptr: 0x2000000000050000, ret: 0x200000000005040e, len: 0x40e
> 
> The found location is already after the buffer. memchr is AFAIK expanded
> by gcc.

Thanks for the clear test case.

Given gcc -S output, I would gladly look it over.

Regards,
Jonathan